While it’s best to book museum/gallery tickets in advance wherever you can (eg Florence’s Uffizi/Accademia or Rome’s Vatican Museums), going solo does mean that if, for whatever reason, you didn’t get advance tickets, you are totally on your own schedule – and can get to the front of any queue bright and early (or later in the day) if you so wish!
In fact, going on your own means that you can do what you want, when you want! In the big cities, you might get gallery fatigue quicker (or slower) than a companion…so take the trip at your own pace. Choose the restaurants and bars that you want to go to, and stay in the hostels/hotels that take your fancy.

How about some cooking classes? But remember how regional Italian food is – the simple Tuscan approach might give you a good basis for hearty dinners back home, for instance. Alternatively, go for pasta- or pizza-making – easy if you know how, apparently!